Cordelia Gray, the protagonist, a twenty-one-year-old detective on her first case. She inherited Pryde’s Detective Agency when her senior partner, Bernie Pryde, committed suicide. Reared in a succession of foster homes and a convent until her father, an itinerant Marxist poet, called her to leave school and assist him as a party organizer, Cordelia has become an extremely self-reliant young woman, accustomed to making her own way in the world. Ironically, this case takes her to Cambridge, the university she was preparing to attend when her father took her from school. This awareness informs her investigation, as does the instruction of her late partner. Most of all, however, she is moved by her increasingly powerful sense of identification with the subject of her investigation, Mark Callender.

Sir Ronald Callender

Sir Ronald Callender, a noted scientist who directs a private laboratory. He displays a cool demeanor and single-minded interest in his work. Sir Ronald hires Cordelia to investigate the motives for the recent suicide of his son Mark. It quickly becomes clear that he and Mark have shared little contact and less affection, so his concern seems surprising to Mark’s friends. At the novel’s conclusion, he dies in what seems to be a suicide.